1. Field of the Invention
The present invention relates to cameras that utilize film strips and, more particularly, to film strip guide systems that are used to position a film strip to facilitate photographic operations.
2. Description of the Related Art
Film strip guide systems for use in cameras are well known. Such systems are used to guide a film strip across an aperture of a camera in order to facilitate photographic operations. In addition to guiding a film strip, guide systems often are designed to flatten a film strip to ensure accurate photographic operations. A typical arrangement of a film strip guide system is illustrated in three drawing figures which are attached hereto and which have been identified as "FIG. 1,""FIG. 2A," and "FIG. 2B," respectively.
In particular, FIG. 1 shows a conventional camera having a camera body 1 that includes an aperture 1a. Inner rails 1b and outer rails 1c guide a film strip across aperture 1a. A separately constructed pressure plate 2 is used to flatten the film strip to facilitate photographic operations within camera 1. In FIG. 1, pressure plate 2 may be fixed to camera body 1a by screws 3 (FIG. 2A). Accordingly, in camera 1, a film path tunnel or channel is formed between pressure plate 2 and camera body 1a through which a film strip may be advanced and re-wound.
FIGS. 2A and 2B, illustrate a film strip 4 within the film path channel shown in FIG. 1. The position of film strip 4 in a vertical direction (V) within camera 1 is maintained by outer rails 1c. The position of film strip 4 in a horizontal direction (H) within camera 1 is maintained by inner rails 1b along with pressure plate 2.
Despite the widespread use of film strip guide systems like or similar to those shown in FIGS. 1, 2A, and 2B, such systems are not without their problems. For example, such systems are not very effective at ensuring the flatness of a film strip to facilitate accurate photographic operations. In particular, it is difficult to ensure such flatness between inner rails 1b and pressure plate 2 as a result of screws 3. Tightening each screw 3 to ensure that pressure plate 2 is mounted exactly parallel to camera body la has been difficult to achieve, especially during automated assembly procedures, etc. As a result, a film strip like film strip 4 is able to maintain a relatively large crown or bow (as shown in FIG. 2B) which can have a negative affect on photographic operations. As such, a particular area of a film strip may be maintained in a position that does not adhere to a particular focus state within camera 1, thus allowing an otherwise focused image to be inaccurately exposed. And, as a result, such inaccurate exposures have produced bad and lost photographs.
Thus, there exists a need to provide a new and improved apparatus for supporting and maintaining a film strip in a camera to facilitate photographic operations. Such an apparatus must ensure film strip flatness without utilizing conventional film path structures such as separately mountable pressure plates, etc. To be viable, such an apparatus should include both a film guide or rail system and an integrally formed pressure plate structure.